Singapore researchers 3D print calamari alternative that surpasses real squid in protein

Researchers at the National University of Singapore have developed a 3D-printed, plant-based calamari alternative that mimics the texture of real squid and offers higher protein content. Using a blend of mung bean protein and microalgae, the study demonstrates the potential of sustainable ingredients and food printing technologies to help reduce pressure on ocean ecosystems and meet rising demand for alternative seafood.

Published in ACS Food Science & Technology, the research was led by Poornima Vijayan and Dejian Huang. The team created a composite ink from mung bean protein isolate and bead-milled microalgae biomass, then 3D printed the mixture into calamari rings. After freezing, battering, and frying the samples, the rings were tested against real squid for texture and protein content.

The most successful formulation, containing 10% microalgae, closely resembled real calamari in terms of hardness, springiness, and cohesiveness. It also delivered 19.61% protein, compared to 14.21% in actual squid rings.

“Our formulation achieved not only a convincing texture but also exceeded the protein content of conventional squid,” the researchers reported. “The combination of mung bean and microalgae offers a promising avenue for the development of sustainable and nutritious seafood alternatives.”

To ensure the printability and structural stability of the composite ink, the team conducted extensive rheological testing. The optimal formula included 1.5% gellan gum and 2% fat in addition to 10% microalgae biomass. This combination allowed the material to exhibit shear-thinning behavior, enabling it to pass smoothly through the printer nozzle while firming up afterward.

Texture analysis showed that calamari rings printed with 10% microalgae reached 192.83 grams in hardness, closely matching the 180.85 grams observed in real squid. Rings without microalgae were significantly firmer at 311.09 grams, lacking the desired elasticity.

Microscopy further confirmed that microalgae created a discontinuous protein matrix with small voids that mimicked the soft, elastic nature of squid flesh. The printed rings remained stable during frying at 180°C for 30 seconds, retaining shape and texture.

The research also addressed the environmental context of traditional seafood production. Overfishing, marine pollution, and seafood contamination – including microplastics and heavy metals – are growing concerns for consumers. By using ingredients like mung beans and microalgae, which require less land and water and are often byproducts of other food industries, the study proposes an alternative with both nutritional and environmental benefits.

Thailand’s mung bean starch industry alone produces roughly 600 metric tons (approximately 1.3 million pounds) of protein-rich wastewater daily. Meanwhile, microalgae can be cultivated on non-arable land with minimal freshwater input, offering scalability without competing with staple crops.

While the results are promising, the study acknowledges certain limitations. Increasing the microalgae content to 20% led to decreased structural integrity during frying. Additionally, the microalgae used had been spray-dried, causing protein denaturation and low solubility (1.14% compared to mung bean protein’s 85.6%). As a result, microalgae acted more as a filler than a fully functional protein.

Flavor profiling and consumer sensory testing were not conducted, and the researchers note these steps will be essential in assessing commercial viability.

The work was supported by the National Research Foundation under the Campus for Research Excellence and Technological Enterprise program. One author received additional support through a Commonwealth Research Scholarship. The authors declared no financial conflicts of interest.

The study, titled 3D Printing for Seafood Mimic: Factors Impacting the Rheology and Texture of Microalgae and Mung Bean Protein Composite Ink, was published on 22 March 2025.